Improvement in printing-presses



UNITED STATES RICHARD M. HOE, OF NEIV YORK, N. Y.

IMPROVEMENT IN PRINTING-PRESSES.

Specflcation forming part of Letters Patent No. 162,651, dated April 27, 1875; application filed May 27, 1h74.

To all whom fit may concern:

Be it known that I, RICHARD M. HOE, of the city, county, and State of New York, have invented certain Improvements in Printing- Presses, of which the following is a specification:

My invention relates to printing-presses which print from a web or roll of paper, and print on both sides, or perfect the sheet; and it consists in a novel construction, combination. and arrangement of parts, and'has for its object to prevent the ink on the `printed side of the sheet setting olf on the second impression-cylinder, betweenwhich and the second type-cylinder the sheet passes for its second impression, as will be fully hereafter set forth.

Figure lis a side elevation. Fig. 2 is a plan or top View, partly in section.

A A are the side frames of the machine;

B, the bed; O, a web or roll of paper to be printed; D, the type or stereotype cylinder, for printing the irst side of the paper; E, its impression-cylinder; F, the second type-cylinder, for printing the second side of the paper; and Gr is its impression-cylinder. The c5 linders D and G are geared together by the three gear-wheels H I K, so as to revolve in unison.

The paper-from the roll C passes between the two pairs of printing and impression cylinders, and is thus printed on both sides. rlhe ink on the freshly-printed side of the sheet would set oft' on the second impression-cylinder G, and after a revolution of this cylinder the printing would be a blur; and to obviate this I interpose a web or strip of paper between the'impression-cylinder and the printed side of the paper, on which the set-off7 is received.

L is a web of paper, rolled on the spindle or Winder M, and which passes under the roller a, and to and around the impressioncylinder-G, between it and the printed paper, and thus it, instead of the cylinder, receives the set-off from the latter. lhe set-off paper is carried forward by the pressure on the printed paper, and must necessarily run at the same speed, and it is received and wound up on the spindle or winder M. This spindle is driven by a belt, N, from a pulley, O, on the outer end of the shaft of the impressioncylinder G to a hanged pulley, P', on the spindle M. The tension of this belt is'regulated by the tightening-pulley Q, so that as the roll on the spindle M increases in diameter, and consequently turns slower, the belt slips around on the flanged pulley P. R is a weight attached to a strap, S, that hangs over the end of the spindle of the roll M, and thus makes sufficient friction to cause the paper that is being drawn off from the spindle M to be tightly stretched.

When the paper has entirely run off the spindle M onto the spindle M the machine is stopped, and the belt N is taken off and replaced by one that will connect the pulley O to the flanged pulley P on the end of the spindle M, and the friction-strap and weight It are transferred to the spindle M. The end ot' the roll of paper on the spindle M is then passed under, up, and around the impressioncylinder G, but between it and theprinted paper, as before described, and thence onto the spindle M, to which it is attached, and, by the-operation of the machine, rewound onto it, but, it will be observed, with the opposite side presented to receive the set-off from the printed sheet, thus giving the setoff ink on the iirst side time to dry before itV is again brought in contact with the printed paper. y

The position and direction ofthe set-oft' web can be readily traced by the dotted lines, and the broken and dotted lines, and the arrows by their sides.

After the paper has become too thickly coated with the set-oft' ink to be of longer use, it can readily be replaced by a new web.

I claim- 1. The combination, with the impressioncylinder G, of the offset web, its windingpulleys M M, and suitable gearing for driving the pulleys alternately in opposite directions to wind the offset web from one pulleyshaft to the other, whereby opposite sides of said offset web vor sheet are alternately pre sented to the printed surface, substantially as described.

2. The combination of impression-cylinder Ir. Y Y

Gr, offset Wel), Winding-pulleys M M', guideand a suitable tension device, changeable roll a, and suitable gearing for driving the from one pulley to the other, substantially es pulleys M M alternately in opposite direedescribed.

tions, substantially as described. RIGHD. M. HOE.

3. The combination of impression-cylinder Witnesses: Gr, offset Web, Winding-pulleys, gearing to CHARLES VERNON PACE,

alternate the motion of the Winding-pulleys, GI-IAs. W. CARPENTER. 

